MacBook Pro just stopped working

My MacBook Pro, only a couple months old, just quit working on me. It shut off and wont turn back in whether it's plugged in or not. It was at full battery when it shut off, too.
I was playing Portal through Steam and had Google Chrome running. That's it.
I did have a modded Xbox controller plugged in, which due to the lack of any other noticeable causes I have to guess the controller might have somehow been the cause?
But if it was...does plugging in a modded 3rd party device void the MacBook's warranty?
And does anyone have any ideas what could have happened?

Make an appointment with your local genius bar to have the machine looked at. I have no idea whether the modified controller had anything to do with your screen blacking out or not. And as far as voiding the warranty, Apple will determine that especially if the controller somehow damaged the machine.